During the 2023 GREEN4SEA Athens Forum, Mr. Peter Quaade, Manager, Head of Dual Fuel Technology group, MAN Energy Solutions, presented the benefits that a ME-LGIP engine offers, such as supporting the use of LPG for propulsion of large merchant marine vessels, giving also potential for global bunkering network as smaller LPG carriers can be used for STS bunker operations. These are designed to be dual fueled with LPG as the low-flashpoint fuel, he explained.
We have more than 1.100 dual fuel engines in our portfolio at the moment. We have 308 dual fuel engines in service. By last year, 2022 of the orders we have, 63% of the total order income is dual fuel engines.
LPG as a marine fuel
We first introduced it in September 2018, where we had a public demonstration at our research facilities in Copenhagen, which was a 50-bore engine. That means, the cylinder diameter is 50 centimeters. Emissions savings on the LPG is for CO2 about 13%.
MAN B&W ME-LGIP Engine
Our LPG fueled engines are designed on a standard MAN ES engine platform. The injection system is what separates the different engines from conventional diesel engines, all our dual fuel engines are on same platform, except for the fuel equipment.
How we build up the engines
Each cylinder have what we call a Gas Block, red arrow, and by ELWI (1) and ELGI (2) valves we are controlling the dual fuel injection. Whether it’s a four (4) or twelve (12) cylinder engine, the design is the same.
Supply pipes (4) and return pipes (5) for each of individual cylinder, are of the so-called double wall pipe design This design we use on all of our dual fuel engines.
The blue piping in the image below is the supply and the surrounding yellow pipe is actually a part of the double roll pipe. In the engine room there will be no exposed gas pipes, everything will be in a double ventilated pipe.
The injection with LPG, it can’t ignite by itself. So, we need to have a pilot injection. This is a very small amount of diesel or heavy fuel or any other fuel that is provided by the first engine. The conventional Fuel Valve will inject this pilot injection when in dual fuel mode, and when running traditional diesel mode the same Fuel Valves used for fuel injection.
For dual fuel running we have the so-called FBIV (Fuel Booster Injection Valve), the valve inject the LPG into the combustion chamber. The supply pressure to the engine is 50 bar, injection pressure is six to seven hundred bar in the combustion chamber. All our dual engines use a pilot injection to ignite the gas; Methane, Ethane, Methanol or LPG.
The typical layout or design for a LPG engine can be seen in below sketch. Below the red dotted line is the engine room, above is all the auxiliary equipment like supply pumps, deck tanks etc.
Talking about the retrofitting prospects and the possibilities, if we look into LPG as the fuel, then we can see all our platforms, except the ME- GA, which is a completely different engine concept. It’s a little bit different cylinder liners and cylinder covers but basically all our platforms can be converted into LPG engines and vice versa other engines can be converted into methanol or anything like that.
MAN ES retrofit solutions:
LPIG – New technology
LGIP is a new technology for us and when we introduce new technology, we also face new challenges.
Atomizers are injectors which inject LPG fuel into the combustion chamber. Mainly, when the analysis of the material, it’s calcium oxide and that turns out to be quite hard and will block slowly of these atomizers. We have introduced different.
The most important is that we recognized some issues and we are step wise sending out these new technologies to the engines in service and new building will of course be updated to latest standard.
Above article has been edited from Mr. Peter Quaade’ presentation during the 2023 GREEN4SEA Athens Forum.
Explore more by watching his video presentation here below
The views presented are only those of the author and do not necessarily reflect those of SAFETY4SEA and are for information sharing and discussion purposes only.
